Clearly a direct conversion is problematic given the wide disparity of the two settings, but the concept of a river cruise “railroad” adventure has merit worth exploring and the Black River, running through occupied territory just cries out for this sort of treatment!
Corvis is a logical embarkation point, not just because of it’s central location and overall importance to the RPG aspect of the Iron Kingdoms setting but also because it fits well as the start of an adventure of this type – there’s even the precedent of a steamboat trip into the bayou in the second original Witchfire trilogy adventure to echo.
On the other hand Merywyn makes for suitable start as well, regardless of this ensuring travel past the occupied Thornwood on the west bank and the savage Widower’s Wood and mysterious Glimmerwood on the east bank provides ample opportunity for both Core and Unleashed style encounters. Traveling on all the way towards Riversmet through the contested Khadoran / Free Llaelese border also has a lot of potential and may align more with the original river journey’s flavour and feel. Alternatively or additionally, the direction of travel can be flipped “downriver” back to Corvis or the overall route retraced depending on the composition and motives of the party, as well as the desire for a river based campaign setting.
The Barge and its Crew
Given the volatile political situation, a Rhulic barge makes sense rather than an unaffiliated or even Cygnaran aligned boat, even if the party are mainly Caspian although safe passage is no guarantee despite the declared neutrality and reassurances of both Cygnar and Khador towards the dwarves. Reinventing “Old Adam”, as a Rhulic steamboat captain fits well enough, perhaps with an Ogrun mate / deckhand (Labor Korune / Pugilist) and a gobber or pyg / trollkin engineer (Field Mechanik / Pirate). The somewhat insidious “Uller” character could be a renegade urban Nyss with motives of his own…
Soviets and regular Warsaw Pact troops become unsurprisingly enough various Khadorans, whereas the locals and militias could be simply represented by the Llaelese resistance or reclusive swampies, leaving marauder encounters as savage kriel Trollkin, tribes of Gatormen or perhaps bands of roving Tharn. Keep the same motivations. relative locations and contexts, just change the uniforms and ramp up the fantasy element, dropping the technology back to breech loaders. Single Career NPCs are the mainstays for leaders, although Battle NPCs with faction or tribal equipment will round out the majority of opponents.